


Daddy's Favorite

by Silver_Centurion



Category: Undertale (Video Game)
Genre: Daddy Kink, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Father/Son Incest, Incest, M/M, Parent/Child Incest, Praise Kink
Language: English
Status: Completed
Published: 2017-11-03
Updated: 2017-11-03
Packaged: 2019-01-28 20:04:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,329
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12614384
Author URL: https://archiveofourown.org/users/Silver_Centurion/pseuds/Silver_Centurion
Summary: A collection of Sans and Gaster fics across many AUs and with many kinks involved.





	Daddy's Favorite

**Author's Note:**

> Classic Sanster: Praise Kink
> 
> This is the first of many self indulgent chapters to come involving this pair. I decided to start this debauchery off with a sweet bang with some good old fashioning love and tenderness.
> 
> Unbeta-ed. I GO DOWN WITH MY SHIP LIKE A REAL MAN TYPOS AND ALL

Some of Sans’ earliest memories are of Gaster and Papyrus when his brother was still just a bitty bones. He remembered when Papyrus was still unable to walk and either had to be carried or allowed to roll across the house. Sans swore he’d never seen a skeleton roll that much, but Gaster had assured him that it was perfectly normal.

His energetic little brother would roll right onto Gasters feet and peep until the taller skeleton picked him up. Gaster would smile and coo at the little bones before gently taking him into his too thin arms.

Sans was suddenly reminded of that little roly poly as he watched Gaster fuss over a small cut above Papyrus’ eye socket. The younger skeleton made his first mistake by asking for a bandaid after a rough training session with Undyne. He should have known better.

“MOTHER PLEASE,” Papyrus whined as Gaster peppered his face with kisses. “I AM A GROWN BONES AND DO NOT NEED MY OWIES KISSED.”

Gaster crooned and refused to let up despite his son all but falling out of his seat to escape the onslaught.

“Oh But I See A Big Bones That Still Can’t Help But Hurt Himself,” Gaster shot back and took Papyrus’ face in his long delicate hands.

Sans was tuning them out as he stared from across the living room. Gasters pure white bones looked like porcelain in the bright light of their home, and just seeing his delicate wrists peeking out from under his black sweater was making Sans’ mouth go dry. He felt his magic stirring at the mental images of those fingers caressing his face, making him come undone as that soft voice uttered praises right into his skull.

“Sans?”

Hearing his own name snapped him out of his fantasy, but it did nothing to help his stirring libido as he hummed, “yeah pops?”

Gaster looked amused, Papyrus still locked in a loving death grip despite his vigorous efforts to free himself.

“You’re Looking A Little Flushed Dear. Are You Feeling Alright?” His head tilted, and his always pleasant smile turned down a little in concern.

“oh me? nah. with you around my health will never go down the toilet,” Sans replied with a long shrug.

Sans almost lost it at Papyrus undignified squawk, but Gasters chuckle was like Giftmas Bells.

“Is That So?” Gaster hummed and released Papyrus from his tyranny.

“I’M FREE!”

Papyrus rocketed up the stairs without even touching the floor, and Sans suddenly felt exhausted.

Ignoring his youngest’s antics completely, Gaster approached Sans and bent down to his level. His eyelights were bright and full of mirth as he took Sans face in his hands, and gave his bones a soft squish.

“Surely My Eldest Boy Isn’t Too Old For Get Well Kisses?”

Sans felt his entire body light up with embarrassment as Gaster placed warm kisses on the fattest part of his cheek bones. They were feather light, and made Sans start to laugh despite himself.

“dad, quit it,” he said with no real desire behind it. With Gaster this close Sans was enveloped in the other skeletons scent. Soft and warm, with a sharp musk of something that reminded him of home, he had no desire to make Gaster stop.

Sans felt his Father smile against his cheek as he said, “But Sans You’re Still So Flushed. Surely You Don’t Want To Come Down With A Fever?”

Each peck sent a shot of warmth straight to Sans soul which thrummed in time with the magic that pulsed around in his pelvis. A soft kiss right below his right eye socket made his eyelights flutter, and Sans made another soft chuckle as he gently took a hold of two of Gasters fingers. His smaller bones barely wrapped around the digit still gently cupping his face, a fact that never failed to get Sans engines revving.

“You’re Such A Good Boy,” Gaster hummed as he tilted Sans head up so he could lavish attention to the vertebrae just under Sans skull. “Did You Know That Sans?”

Sans throat suddenly felt dry as Gaster laid firm kisses down the front of his neck. His father’s slender hands slipped from his face down to the front of his chest to gently rub at the bones through his shirt, resulting in making his eldest son groan.

It felt nice, the soft pressure of Gasters fingers was warming his bones, and as Gaster gently nipped at his clavicle in just the right way Sans swore he saw stars.

“My Good Boy…” He cooed again and Sans let out a breathless laugh.

“how good am i?”

Gaster let out another chuckle, letting his deep purple tongue dart out to lick sans exposed collarbone.

“Mmm The Best…Daddy’s Favorite,” the older skeleton teased.

Both of them knew that Gaster never actually picked favorites. Both of his boys knew he loved them unconditionally and equally, but that didn’t stop him from occasionally pulling out that card when he felt like being playful. Usually it was so he could coy his way into making the boys do extra chores. Now he was using it as a modified weapon against Sans’ fragile psyche.

Those words went straight to his groin, which had been undecided until now, and his magic condensed and formed a dick that immediately tented his shorts.

“h-hey careful….you know what that does to me,” Sans said with another embarrassed laugh.

“Oh?” Gaster looked up at him feigning ignorance. “But It’s True Sans! You Are My Favorite. My Smartest, Most Handsome Boy,” Gaster said with a laugh of his own but Sans knew he meant it.

Sans had a witty retort on the tip of his tongue, but it was cruelly ripped away and turned into a moan as one of Gaster’s hands slipped even further down to cup his modest cock through his shorts.

Sans quickly became one with the couch as Gaster started to whisper soft praises and gently message his dick with those beautiful fingers. Sans felt like his body was turning into jelly as he Fathers own personal brand of love warmed his entire core. Suddenly pent up and hungry for both the praise and the stimulation, he arched up off the couch with a soft whine escaping his clenched teeth.

Gaster shushed him and began trailing soft kisses across his face again—Gaster going over his nose ridge, down below his eye, a soft clack of their teeth end then back to his neck.

“I’ll Take Care Of You Sans. Shhh Sweet Boy Just Let Daddy Take Care Of You.”

Sans vision dotted with stars as he came unexpectedly in his shorts. Gaster didn’t stop palming him much to Sans delight, but his face burned from embarrassment at how quickly he became undone under Gasters soft attentions.

Gaster pulled away, and Sans could see his Fathers eyelights were bright from arousal as he tsked.

“I Suppose Even Good Boys Make Messes,” he teased and gently clacked their teeth as Sans laughed.

“sorry dad…guess your potty mouth was too much for the little guy to handle.”

Gaster shook his head as his smile widened.

“More Toilet Humor? Sans I Know I Raised You Better Than That.”

“hey pops don’t you know? everyone else thinks my humor is shit. maybe you need to get with the program.”

Gaster laughed again as he gathered up Sans in his arms. Gaster’s thin frame always held more strength than it first appeared, and despite Sans sizable girth in comparison to his lean father the taller skeleton was able to cradle Sans with ease.

“Well How About I Clean You Up, Dirty Boy, And Then We Can Work On Your Material Before Your Career Goes Down The Drain,” he said as he waddled up the stairs with his sleepy cargo. Sans could fall asleep like this if Gaster would let him, but the promise of a bath was much more appealing.

**Author's Note:**

> Some of you may be curious about why I wrote some things in the way I did. I personally headcannon Classic Gaster to be rather gender ambiguous in his actions, with a delicate build and a smooth voice. As a baby Pap called him Mommy and Gaster never bothered to correct him, so he responds to both Mother and Father.
> 
> I know it's not everyones cup of tea but I enjoy writing each Gaster with a few different quirks.
> 
> Thanks for reading!


End file.
